These studies are designed to evaluate the use of One Cell Systems' novel encapsulation technology to facilitate in vitro growth and differentiation of immature (fetal or neonatal) pancreatic islets isolated from porcine and bovine donors. This technology provides a means for encapsulating single islets within a microdrop which then allows the islets to be cultured in a stable, physically discreet, three-dimensional matrix. Using this culture system, the effect of a variety of agents such as growth factors and extracellular matrix components on fetal islet growth and maturation will be determined. The gel microdrop (GMD) culture system can be combined with flow cytometry to provide a rapid and efficient automated method for analysis of growth and hormone secretion using fluorescence-activated cell sorting. Specific subpopulations of islets obtained from immature glands can then be identified and recovered on the basis of a mature insulin secretory response. The establishment of an in vitro system for culture and maturation of fetal or neonatal islets from commercially used animals such as the pig or cow would facilitate further progress in islet transplantation techniques and could address unresolved issues in islet development. PROPOSED COMMERCIAL APPLICATION: Development of an in vitro system for culturing and maintaining fetal or neonatal islets would contribute to the development of successful transplantation methods. Initially this system will be used by diabetes researchers and could eventually be used by companies focused on transplantation strategies.